The current is conventionally detected by using a shunt resistor, which measures a voltage caused by the current flowing through the shunt resistor in various kinds of current detections. The detections include, detection of electrical charge and discharge current in a battery, detection of motor current that drives an electric vehicle or a hybrid-power car etc., detection of current in electric equipment such as air conditioner, and detection of current in power generating machines including solar battery etc.
In case of a bus bar used as a current path from power supply such as batteries to various electrical equipment, the shunt resistor for current detection must be connected with the bus bar. In such a case, the bus bar and the shunt resistor are conventionally connected with screw fastening or soldering for fixing a terminal or an electrode of the shunt resistor and a terminal of the bus bar (see Japanese laid open patent publication 2011-003694).
However, according to such connection between the bus bar and the shunt resistor, because of increase of connection point, heat generation occurs by contact resistance of the connection between them, and problem of securing connection reliability occurs. Then, a current detection device that can be used for detecting a large current with high reliability is required. Japanese laid open patent publication 2008-039571 discloses a bus bar type shunt resistor, which includes a first wiring member, a second wiring member, and a resistor body welded and fixed between the first and the second wiring members (see FIG. 6 etc.).